Electrical coupling what's it called?

What are you trying to couple? There are EMT couplings, standard and water tight, threaded conduit couplings, three piece Erickson couplings, explosion proof couplings...

You said "the platform can only turn one way, so it can't have wires up the hub."

this sentence is unclear.......turning one way does not preclude putting wires up through the hib

Does the platform do continuous 360's? Like display platform? Like the turret in a tank?

If yes, you need a "slip ring"

These are very seldom used & most elctrivcal house's won't stock thme

cheers

Google for "electrical slip ring" . There are many hits.

It's called a slip ring, sometimes called a commutator ring (a commutator ring is a specialized type of slip ring.)

My apologies.

Eventually they'd twist off.

Exactly like that.

Google will now be my friend! :)

So I've been finding out...

Thanks.

That's the kind of thing I'm looking for. Thanks much!

They are called slip rings. There are a number of designs, but typically it's a couple rings of brass with carbon brushes that press against them to conduct the electricity. They are used on everything from tank turrets to ferris wheels. Very similar to the commutator on a DC motor, but the rings are not segmented and provide a continuous connection.

Pete C.

Slip rings are used all over the place. They are very, very common, but they are not a typical "off the shelf" item in most cases. The Thomas Register lists some companies that make them commercially, but they're fairly high end and expensive.

In many cases the company or person making the item that needs the slip rings makes the slip rings as well as they are pretty simple. Any electric motor shop will have a nice assortment of carbon brushes you can use and probably brush holders as well.

I built a display carousel that needed to couple 12VAC power across the rotary connection and I built the slip rings from a couple segments of brass plumbing pipe mounted on PVC pipe with carbon brushes from an auto parts store pressing on them.

Pete C.

I have seen them in a device to keep a telephone handset cord from getting tangled.

I can't say who makes them, but I've seen a cheap consumer slip ring for lights used on rotating Christmas trees.

Beachcomber

Hah! They do still make them! Check this out... Rotating Christmas Tree stand with slip rings!